A triangle has side lengths of 6, 6, and 9 units. A similar but larger triangle has side lengths of 12, 12, and 18 units. Calculate and compare the perimeters of the two triangles. What is the ratio of the perimeter of the smaller triangle to the perimeter of the larger triangle?

1 answer

To find the perimeters of the two triangles, we start with the first triangle which has side lengths of 6, 6, and 9 units. The perimeter \( P_1 \) of this triangle can be calculated as follows:

\[ P_1 = 6 + 6 + 9 = 21 \text{ units} \]

Next, we calculate the perimeter \( P_2 \) of the larger triangle with side lengths of 12, 12, and 18 units:

\[ P_2 = 12 + 12 + 18 = 42 \text{ units} \]

Now, we need to find the ratio of the perimeter of the smaller triangle to the perimeter of the larger triangle:

\[ \text{Ratio} = \frac{P_1}{P_2} = \frac{21}{42} \]

This ratio simplifies to:

\[ \frac{21}{42} = \frac{1}{2} \]

Therefore, the perimeter of the smaller triangle is half that of the larger triangle, and the final answer is:

\[ \text{The ratio of the perimeter of the smaller triangle to the perimeter of the larger triangle is } \frac{1}{2}. \]